quest on taxes and different brackets?

ok yall this my bracket this year---

15%
$9,325 to $37,950
$932.50 plus 15% of the excess over $9325

I am anticipating return of of 3-4k this year and i claim 0 on my w2s. Got health insurance so wont get dinged the 700$ fee this year. so i already lose about 30% of my income...well with in the next month i am picking up another job to work for a year so ill be login 70- 80hours a week, so i will have a estimated of income will be about $45000-51000 which is pretty good for being 23 with out a degree i so pose.

i will now be the next bracket of....
25%
$37,950 to $91,900
$5,226.25 plus 25% of the excess over $37,950
28%

not sure how is going to work? im getting taxed 25% already am i now going to get taxed 53% on each check from both different jobs?so am i automatically going to get taxed 5226$ when i go to pay my taxes and 25% more of $13000? so if i see this right it looks like i will owe money at end of the year even though my paying 50% of my income right or wrong???











Table 1. Single Taxable Income Brackets and Rates, 2017
Rate
Taxable Income Bracket
Tax Owed

10%
$0 to $9,325
10% of Taxable Income

15%
$9,325 to $37,950
$932.50 plus 15% of the excess over $9325

25%
$37,950 to $91,900
$5,226.25 plus 25% of the excess over $37,950

28%
$91,900 to $191,650
$18,713.75 plus 28% of the excess over $91,900

33%
$191,650 to $416,700
$46,643.75 plus 33% of the excess over $191,650

35%
$416,700 to $418,400
$120,910.25 plus 35% of the excess over $416,700

39.60%
$418,400+
$121,505.25 plus 39.6% of the excess over $418,400